1. Field of the Invention
The present invention relates to methods and apparatus for fixation of sutures and soft tissue to bone using a screw or plug.
2. Description of the Related Art
When soft tissue such as a ligament or a tendon becomes detached from a bone, surgery is usually required to reattach or reconstruct the tissue. Often, a tissue graft is attached to the bone to facilitate regrowth and permanent attachment. Various fixation devices, including sutures, screws, staples, wedges, and plugs have been used in the past to secure soft tissue to bone. In typical interference screw fixation, for example, the graft is fixed to the bone by driving the screw into a blind hole or a tunnel in the bone while trapping the end of the graft between the screw and the bone tunnel. In other methods, the graft is simply pinned against the bone using staples or sutures tied around the end of the graft to the bone.
More recently, various types of threaded suture anchors have been developed. The application of such suture anchors generally requires the surgeon to tie knots in the suture to secure the tissue to the bone, which is tedious and time-consuming. The surgical procedure would be less cumbersome for the surgeon and ultimately more beneficial to the patient if the tissue could be attached to the bone without the surgeon having to tie suture knots.
The present invention provides a surgical technique and associated device for securing soft tissue to bone with excellent pull-out strength and which does not require the surgeon to tie suture knots to secure the tissue to the bone. The present invention may be used to secure any type of soft tissue, graft, or tendon, such as, for example, a biceps tendon or a rotator cuff.
In a preferred embodiment of the invention, a blind hole or socket is created in the bone at the location that the graft is to be secured. Suture is passed through the graft at desired points. A cannulated plug or screw is pre-loaded onto the distal end of a cannulated driver. In a preferred embodiment, a separate piece of suture is passed through the cannula of the driver, with a looped end of the suture exposed at the distal end of the driver. The ends of the suture attached to the graft are fed through the suture loop at the end of the driver. Tension is placed on the suture to bring the graft to an appropriate distance from the distal end of the driver. Here, the graft is either brought to the distal end of the driver or spaced away from the distal end of the driver by a distance approximately equal to the length of the screw or plug. The distal end of the driver is inserted into the bottom of the hole, with the screw or plug disposed just outside the hole. Once adequate tension is achieved on the suture to keep the graft at the desired location relative to the bone hole and the distal end of the plug or screw, the driver is pressed into the hole, engaging the first thread or bump of the screw or plug. The screw or plug is then fully advanced into the hole using the driver to frictionally secure either the suture attached to the graft or the graft itself into the bone hole. When the screw or plug is fully inserted, the suture loop is freed and the driver is removed. The loose ends of the sutures protruding from the anchor site are then clipped short.
Alternatively, the step of passing suture through the graft may be omitted, so that the graft itself is captured in the suture loop to be directly affixed into the fixation hole.
In another alternative, the suture loop through the driver may be omitted, and the graft is positioned relative to the driver by inserting the ends of the suture attached to the graft into and through the cannula of the driver from the distal end thereof.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.